1. Field of the Invention
The present invention relates systems and methods for downscaling an image. In particular, the present invention relates to skipping one or more scan lines of an original image, skipping one or more additional pixels of the original image, and using the remaining pixels of the original image to efficiently downscale the original image.
2. Background and Related Art
The emergence of the personal computer and associated computer applications has allowed text and/or graphics to be displayed or printed in a variety of different ways. One such way of displaying or printing text and/or graphics includes the use of a “thumbnail,” which is a miniature representation of a page or image. A particular thumbnail may be displayed to provide a preview of an entire page. Thumbnails enable a user to view the layout of many pages at once on a screen. For example, a plurality of thumbnails may be displayed on a computer screen at the same time to provide a quick preview of a computer presentation that has been created. Thumbnails also provide a convenient way to browse through multiple images, and are typically associated with programs that allow a user to click on the thumbnail in order to retrieve the full image.
A thumbnail may be created through the use of a program that is a stand-alone application or is part of a desktop publishing or graphics program. When thumbnails are too small to show actual text, a process referred to as “greeking” may be used to approximate the text characters in order to indicate how the page will appear.
While the use of a thumbnail as a miniature representation of a page or image can prove to be advantageous to a user, the technique requires considerable time to generate the thumbnail because of the large ratio of downscaling that is required. For example, when the process referred to as “local averaging” is used to scale down the size of an original image to one-third on each dimension, each three by three area of the image is averaged in order to obtain corresponding pixel values for the thumbnail image. This process has proven to be slow, especially when a large number of images are reduced. For example, if a user desires to print a letter-sized (8½″×11″) page containing 80 images of the original size 2048×1536 pixels, it can take over a minute and ten seconds just to perform the scaling.
Thus, while techniques are available for use in creating a thumbnail image, challenges still exist such as requiring considerable time to generate the thumbnail due to the large ratio of downscaling that is required. Accordingly, it would be an improvement in the art to augment or even replace current techniques with other techniques.